PETROGRAPHIC ANALYSIS OF POTTERY FOR THE RIO NUEVO PROJECT, WITH A CASE STUDY OF TEMPORAL TRENDS IN HISTORIC ERA NATIVE AMERICAN POTTERY PRODUCTION

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1 CHAPTER 6 PETROGRAPHIC ANALYSIS OF POTTERY FOR THE RIO NUEVO PROJECT, WITH A CASE STUDY OF TEMPORAL TRENDS IN HISTORIC ERA NATIVE AMERICAN POTTERY PRODUCTION Elizabeth J. Miksa, Carlos P. Lavayen, and Sergio F. Castro-Reino, Desert Archaeology, Inc. INTRODUCTION Petrographic modal analysis, or point counting, is a detailed microscopic analytical technique used to establish the mineralogical composition of a rock or sediment. It has been used extensively to establish composition and provenance of archaeological ceramics, especially in the Greater Southwest. For the Rio Nuevo Archaeology project, 56 sherds from the Clearwater site, AZ BB:13:6 (ASM), and the Tucson Presidio, AZ BB:13:13 (ASM), were selected for petrographic analysis to establish their provenance and to verify the temper characterizations provided by ceramicist James M. Heidke. The sherds are a subset of the 2,373 sherds chosen for detailed ceramic analysis (Chapter 7, this report). They comprise plain and red wares from prehistoric and historic contexts (Table 6.1). The provenance analysis was conducted using the Tucson Basin petrofacies model. The Tucson Basin and Avra Valley have been a focus of petrographic sand temper studies for over 20 years. More than 500 sand samples have been collected and point counted, and statistical models have been developed to define petrofacies, or distinct sand composition zones, within the basin (Figure 6.1) (Lombard 1987; Miksa 2003, 2006). Many of these petrofacies are very limited in geographic extent, so that compositional changes are detailed on scales of kilometers to tens of kilometers. Excavation and subsurface sampling have shown that the sand composition at the surface has remained essentially unchanged for the last several thousand years. Therefore, the petrofacies model provides a way to compare the sand temper in sherds to the actual locations from which sand of various compositions could be procured. Ethnographic data from around the world indicate that potters who use sand for temper tend to procure it within 3 km most often from within 1 km of their pottery production location (Arnold 1985; Heidke 2006). These data are based on people who use only human labor to carry their materials boats, beasts of burden, or vehicles of any sort are not included. Thus, we feel comfortable in asserting that the provenance of the sand temper in pottery indicates the provenance of the pottery itself. METHODS Temper characterization was conducted under a Unitron ZSM stereozoom microscope with magnifications of 6x to 30x. A three-part temper identification code was used: (1) temper type (TT) records what type of material was used (sand, grog, and so forth); (2) generic temper source (TSG) records the general temper composition and the likely group of petrofacies to which the temper belongs; and (3) specific temper source (TSS) records the specific petrofacies to which the ceramicist thinks the temper should be assigned. Unfortunately, the temper characterization for Rio Nuevo was conducted prior to completion of the formal Tucson Basin petrofacies model. Consequently, while Heidke knew the major petrofacies in the Tucson Basin from extensive previous experience, less well-characterized, rarely encountered petrofacies were not fully included in his analysis. The full statistical model and descriptions are available as of this writing, and the petrographic verification was conducted with the completed mode. However, any errors or omissions must be evaluated in the light of the incomplete information available to Heidke at the time of temper characterization. The most notable additions to the model are better characterization of the granitic and mixed lithic petrofacies. These include the basin fill and the bajada petrofacies that have volcanic input. In particu-

2 6.2 Chapter 6 Table 6.1. Inventory of sherd samples from the Rio Nuevo Archaeology project submitted for petrographic analysis. Sample Number AZ (ASM) Site Number Feature Number Field Number Obs Ceramic Type RNA2-01 BB:13: Indeterminate red RNA2-02 BB:13: Indeterminate red RNA2-03 BB:13: Indeterminate red RNA2-04 BB:13: Unspecified plain ware RNA2-05 BB:13: Indeterminate red RNA2-06 BB:13: Indeterminate red RNA2-07 BB:13: Unspecified plain ware RNA2-08 BB:13: Indeterminate red RNA2-09 BB:13: Indeterminate red RNA2-10 BB:13: Indeterminate red RNA2-11 BB:13: Indeterminate red RNA2-12 BB:13: Indeterminate red RNA2-13 BB:13: Indeterminate red RNA2-14 BB:13: Indeterminate red RNA2-15 BB:13: Indeterminate red RNA2-16 BB:13: Indeterminate red RNA2-17 BB:13: Sobaipuri Plain (folded rim) RNA2-18 BB:13: Unspecified plain ware RNA2-19 BB:13: Unspecified plain ware RNA2-20 BB:13: Unspecified plain ware RNA2-21 BB:13: Papago Plain RNA2-22 BB:13: Papago Red RNA2-23 BB:13: Papago Red RNA2-24 BB:13: Indeterminate red RNA-39 BB:13: Sobaipuri Plain (folded rim) RNA-40 BB:13: Unspecified plain ware RNA-41 BB:13: Sobaipuri Plain (folded rim) RNA-42 BB:13: Unspecified plain ware RNA-43 BB:13: Unspecified plain ware RNA-44 BB:13: Papago Red RNA-45 BB:13: Papago Plain RNA-46 BB:13: Unspecified plain ware RNA-47 BB:13: Indeterminate red RNA-48 BB:13: Unspecified plain ware RNA-49 BB:13: Sobaipuri Plain (folded rim) RNA-50 BB:13: Unspecified plain ware RNA-51 BB:13: Sobaipuri Plain (folded rim) RNA-52 BB:13: Sobaipuri Plain (folded rim) RNA-53 BB:13: Unspecified plain ware RNA-54 BB:13: Indeterminate red RNA-55 BB:13: Sobaipuri Plain (folded rim) RNA-56 BB:13: Unspecified plain ware RNA-57 BB:13: Indeterminate red

3 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.3 Table 6.1. Continued. Sample Number AZ (ASM) Site Number Feature Number Field Number Obs Ceramic Type RNA-58 BB:13: Papago Plain RNA-59 BB:13: Papago Red RNA-60 BB:13: Papago Red RNA-61 BB:13: Papago Plain RNA-62 BB:13: Papago Plain RNA-63 BB:13: Papago Red RNA-64 BB:13: Papago Plain RNA-65 BB:13: Papago Red RNA-66 BB:13: Papago Plain RNA-67 BB:13: Papago Plain RNA-68 BB:13: Papago Red RNA-69 BB:13: Papago Plain RNA-70 BB:13: Papago Plain lar, the petrofacies model of the floor of the Tucson Basin proper bounded by the Santa Cruz River on the west, the Rillito River on the north, the Pantano Wash on the east, and approximately the town of Sahuarita on the south has undergone major changes. The floor of the Tucson Basin is an agglomeration of alluvial sediments that have accumulated over thousands of years. Gradational composition changes occur from south to north and from east to west. Determining where to draw petrofacies boundaries in this very gradational sedimentary environment has been challenging. In 2003 and 2004, additional samples were collected from the southern end of the basin, near Sahuarita, and at the southeastern corner, near Pantano Wash and Cienega Creek. Additionally, samples from the Rincon Petrofacies were reanalyzed. In some cases, new thin sections were made, because the original thin sections were uncovered and unstained, hampering detailed mineralogical analysis. Finally, we tested our ability to distinguish sands from provisionally assigned petrofacies on the basin floor from one another in hand-sample. With this new information available, we concluded that we could not reliably distinguish the provisional petrofacies in hand-sample. The gradational compositions of the basin floor make boundary definitions difficult. The new samples, the reanalysis, and the handsample testing led to several changes. The new petrofacies map is provided in Figure 6.1. The most notable changes are among the petrofacies on the floor of the Tucson Basin and in the Black Mountain area. The Black Mountain Petrofacies was previously characterized based on only three samples. Collection of additional samples has significantly improved the definition of the Black Mountain Petrofacies. This improved definition was not available to Heidke when he characterized temper in Rio Nuevo project sherds, so he could not easily identify this area as a potential source. A full description of the changes is provided in Miksa (2006). Petrographic Analysis The 56 sherds selected for petrographic analysis were sent to Quality Thin Sections of Tucson, Arizona, for standard thin-section preparation, including staining for calcium and potassium to allow to be easily recognized. Detailed petrographic analysis was done for each thin section using the methods outlined in Miksa and Heidke (2001). The Gazzi-Dickinson method was used to point count all samples for provenance analysis (Dickinson 1970; Miksa and Heidke 2001). This method treats each sand-sized grain as an individual mineral. It provides detailed mineralogical composition of the sample, and allows for comparisons of sands and sand tempers that may be more mature or less mature that is, more or less broken down into their constituent grains. A standard set of point-count parameters, developed for the Tucson Basin, was used for the analysis (Table 6.2) (Miksa 2003, 2006). The point-count data collected for each sherd are provided in Table 6.3, while the qualitative petrographic data collected for each sherd are provided in Table 6.4.

4 6.4 Chapter 6 TUCSON BASIN PETROFACIES Silverbell Mountains Roskruge Mountains Wash McClellan Santa Cruz River C D W V 6 T U R Wash Y 2 Brawley F Durham 1 Marana Wash Coronado Q MW O Derrio L Canyon E1 M Wash N J3 J2 K E3 J1 E2 Canada del H Big Wash Oro 3 4 Tucson Sutherland Wash Julian Wash I S B/BV A A Rincon B Catalina BV Catalina Volcanic C Samaniego D Avra E1 Western Tortolita E2 Central Tortolita E3 EasternTortolita F Durham G Santa Rita B 5 Watershed Boundary Pantano 8 Rincon Wash Santa Catalina Mountains Creek A H Jaynes I Airport J1 Beehive J2 Twin Hills J3 Wasson K Black Mountain L Golden Gate M Rillito MW Rillito West N Owl Head O Sierrita P Green Valley Q Amole R Batamote S Sutherland T Recortado U Cocoraque V Dos Titos W Waterman Y Roskruge Rincon Mountains 1 P G Santa Cruz River Brawley Wash Canada del Oro Rillito Creek Pantano Wash McClellan Wash Tanque Verde Creek Trunk Stream Green Valley Ma d e r a Santa Rita Mountains Canyon Miles 0 5 Kilometers Petrofacies boundary and designation A R Limit of sampling Used in statistical model for this project Not used in statistical model Watershed Boundary Desert Archaeology, Inc N Figure 6.1. Current petrofacies map of the Tucson Basin.

5 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.5 Table 6.2. Point-count parameters and calculated parameters used for the petrographic analysis of Tucson Basin sands and sherds. Parameter Description Totals and Calculated Parameters Total temper The total number of point-counted sand-sized grains, including crushed rock, clay lumps, fiber temper, or grog. Voids The total number of open voids encountered in the paste. Paste Paste percent Grog Clay lump Sand total The total number of points counted in the silt- to clay-sized fraction of the paste. The proportion of points in the silt- to clay-sized fraction of the paste (Paste/[Paste + Total Temper]) x 100. Sherd temper: dark, semiopaque angular-to-subround grains, with discrete margins, including siltto sand-sized temper grains in a clay matrix, with or without iron oxides and/or micas. The grains differ in color and/or texture from the surrounding matrix of the "host" ceramic. This parameter is counted only in sherd samples. Discrete "lumps," or grains, of untempered clay. These are generally in the sand-sized range. They comprise clay that lacks silt- to sand-sized grains. These grains are often similar in color to the surrounding paste, but they have well-defined, abrupt boundaries. Their internal texture is finer than the paste and has a different orientation. They are assumed to be clay that was insufficiently mixed with the surrounding clay body. The total number of point-counted sand grains; i.e., total temper minus clay lumps and grog. Monomineralic Grains Qtz Kspar Micr Sanid Plag Plagal Plaggn Musc Biot Chlor Px Amph Oliv Opaq Epid Sphene Gar All sand-sized quartz grains, except those derived from, or contained within, coarse-foliated rocks; unstained. Alkali, except those derived from, or contained within, coarse-foliated rocks; potassium stained yellow, unstained plagioclase, perthite, antiperthite. Microcline/Anorthoclase: alkali, with polysynthetic (cross-hatch) twinning; stained yellow or unstained. Sanidine; volcanic alkali. Plagioclase, stained pink, except grains derived from, or contained within, coarse-foliated rocks. Grains commonly have albite twinning and/or carlsbad twinning. Alteration, sericitization affect less than 10 percent of the grain. Altered plagioclase, except grains derived from, or contained within, coarse-foliated rocks. Alteration affects 10 percent to 90 percent of the grain; alteration products include sericite, clay minerals, carbonate, epidote. Considerably altered plagioclase, except grains derived from, or contained within, coarse-foliated rocks; alteration affects more than 90 percent of the grain. Muscovite mica. Biotite mica. Chlorite group minerals. Undifferentiated members of the pyroxene group. Undifferentiated members of the amphibole group. Olivine. Undifferentiated opaque minerals, such as magnetite/ilmenite, rutile, and iron oxides. Undifferentiated members of the epidote family (epidote, zoisite, clinozoisite). Sphene. Undifferentiated members of the garnet group.

6 6.6 Chapter 6 Table 6.2. Continued. Parameter Description Monomineralic Grains in Coarse-foliated Rocks Sqtz All quartz derived from, or contained within, coarse-foliated rocks. Skspar Potassium derived from, or contained within, coarse-foliated rocks. Splag Plagioclase derived from, or contained within, coarse-foliated rocks. Smusc Muscovite mica derived from, or contained within, coarse-foliated rocks. Sbiot Biotite mica derived from, or contained within, coarse-foliated rocks. Schlor Undifferentiated chlorite group minerals derived from, or contained within, coarse-foliated rocks. Sopaq Undifferentiated opaque minerals derived from, or contained within, coarse-foliated rocks. Metamorphic Lithic Fragments Lmvf Lmss Lmamph Lma Lmt Lmtp Lmm Lmf Metamorphosed volcanic rock such as rhyolite. Massive-to-foliated aggregates of quartz and grains with relict phenocrysts of. Metamorphosed sedimentary rock, such as a meta-siltstone. Massive fine-grained aggregates of quartz and, with or without relict sedimentary texture. Amphibolite: a high-grade metamorphic rock, composed largely of amphibole. Quartz- (mica) aggregate: quartz,, mica, and opaque oxides in aggregates with highly sutured grain boundaries but no planar-oriented fabric; some are schists or gneisses viewed on edge; some are metasediments or metavolcanics. Quartz--mica tectonite (schists or gneisses): quartz,, micas, and opaque oxides, with strong planar oriented fabric; often display mineral segregation with alternating quartz-felsic and mica ribbons. Grains are often extremely sutured and/or elongated. Phyllite: like Lmt, but the grains are silt-sized or smaller, with little or no mineral segregation. Also argillaceous grains, which exhibit growth of planar-oriented micas, silt-sized or smaller. Microgranular quartz aggregate: non-oriented polygonal aggregates of newly grown, strain-free quartz crystallites, with sutured, planar, or curved grain boundaries. Foliated quartz aggregate: planar-oriented fabric developed in mostly strained quartz crystals with sutured crystallite boundaries; quartzite. Volcanic Lithic Fragments Lvf Lvfb Lvi Lvm Lvv Lvh Felsic volcanic such as rhyolite: microgranular nonfelted mosaics of submicroscopic quartz and, often with microphenocrysts of, quartz, or rarely, ferromagnesian minerals. Groundmass is fine to glassy, always has well-developed potassium (yellow) stain, may also have plagioclase (pink) stain. Biotite-bearing felsic volcanic: microgranular nonfelted mosaics of submicroscopic quartz and, often with microphenocrysts of, quartz, always with phenocrysts of biotite. Groundmass is fine to glassy, always has well-developed potassium (yellow) stain. Intermediate volcanic rock such as rhyodacite, dacite, latite, and andesite. Basic volcanic: visible microlites or laths of crystals in random-to-parallel fabric, usually with glassy or devitrified or otherwise altered dark groundmass; often with phenocrysts of opaque oxides, occasional quartz, olivine, or pyroxene. Rarely yellow stained, often very well-developed pink stain, representing intermediate-to-basic lavas, such as latite, andesite, quartz-andesite, basalt, or trachyte. Glassy volcanics: vitrophyric grains, showing relict shards, pumiceous fabric, welding, or perlitic structures; sometimes with microphenocrysts, representing pyroclastic or glassy volcanic rocks. Hypabyssal volcanics (shallow igneous intrusive rocks): equigranular anhedral-to-subhedral -rich rocks, with no glassy or devitrified groundmass, coarser-grained than Lvf, most have yellow and pink stain.

7 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.7 Table 6.2. Continued. Parameter Description Sedimentary Lithic Fragments Lss Siltstones: granular aggregates of equant subangular-to-rounded silt-sized grains, with or without interstitial cement. May be well-to-poorly sorted, with or without sand-sized grains. Composition varies from quartzose to lithic-arkosic, with some mafic-rich varieties. Lsa Argillaceous: dark, semiopaque, extremely fine grained without visible foliation, may have mass extinction, variable amounts of silt-sized inclusions, representing shales, slates, and mudstones. Lsch Chert: microcrystalline aggregates of pure silica. Lsca Caco Carbonate: mosaics of very fine calcite crystals, with or without interstitial clay- to sand-sized grains. Most appear to be fragments of soil carbonate (caliche) and are subround to very round. Sand-sized calcium carbonate minerals. Technically, these should be listed with the monocrystalline grains, but they most often co-occur with caliche or other sedimentary rocks. Unknown and Indeterminate Grains Unkn Grains that cannot be identified, grains that are indeterminate, and grains such as zircon and tourmaline that occur in extremely low percentages. Calculated Parameters Used in the Statistical Analyses TQtz TKspar K TPlag F TMusc TBiotchlor Mica Pyr Plagpyr TOpaq Pyrepid PyrOpaq Hmin Lma2 Lmatp Lmmftp Lmmf Lm Lm_Musc Lvf2 Lvm2 Lvmf2 Lv Ls Lsclas Lscaco Qtz + Sqtz Kspar + Skspar Kspar + Skspar + Micr + Sanid Plag + Plagal + Plaggn + Splag Kspar + Skspar + Micr + Sanid + Plag + Plagal + Plaggn + Splag Musc + Smusc Biot + Sbiot + Chlor + Schlor Musc + Smusc + Biot + Sbiot + Chlor + Schlor Px + Amph Tplag + Pyr Opaq + Sopaq Pyr + Epid Pyr + Topaq Pyr + Topaq + Tbiotchlor Lma + Lmamph + Lmss + Lmvf + Lmepid Lma2 + Lmt + Lmtp Lmm + Lmf + Lmt + Lmtp Lmm + Lmf Lmm + Lmf + Lma + Lmamph + Lmss + Lmvf + Lmepid + Lmt + Lmtp Lm + Tmusc Lvfb + Lvf Lvi + Lvm Lvfb + Lvf + Lvi + Lvm Lvfb + Lvf + Lvi + Lvm + Lvh + Lvv Lss + Lsa + Lsch + Lsca + Caco Lss + Lsa + Lsch Lsca + Caco

8 6.8 Chapter 6 Table 6.3. Point-count data for the thin-sectioned sherds. A. Inventory, total points counted and paste characterization Petrofacies Obs a Petrologists' Temper Type Total Grains Counted Paste Voids Fiber Voids Grog Sample No. Sample Type RNA2-01 Sherd H2 1 Sandy clay (may have crushing features) RNA2-02 Sherd J1 1 Sand RNA2-03 Sherd J1 2 Sand and crushed rock, where crushed rock >25% RNA2-04 Sherd J1 1 Sand RNA2-05 Sherd K 1 Sand RNA2-06 Sherd J1 1 Sand RNA2-07 Sherd J1 1 Sand RNA2-08 Sherd J1 1 Sand RNA2-09 Sherd J1 1 Sand RNA2-10 Sherd K 1 Sand RNA2-11 Sherd J1 1 Sand RNA2-12 Sherd J1 1 Sandy clay (may have crushing features) RNA2-13 Sherd J1 1 Sand plus grog RNA2-14 Sherd J1 1 Sand plus grog RNA2-15 Sherd J1 1 Sandy clay plus grog RNA2-16 Sherd J1 1 Sand plus grog RNA2-17 Sherd J1 1 Sand plus grog RNA2-18 Sherd J1 1 Sand plus fiber temper RNA2-19 Sherd J1 1 Sand plus fiber temper RNA2-20 Sherd J1 1 Sandy clay plus grog RNA2-21 Sherd?G 1 Sand plus fiber temper RNA2-22 Sherd K 1 Sand plus fiber temper RNA2-23 Sherd J2 1 Sand plus fiber temper RNA2-24 Sherd J1 1 Sand RNA-39 Sherd K 1 Sand RNA-40 Sherd J1 1 Sand RNA-41 Sherd K 1 Sand RNA-42 Sherd J2 1 Sand RNA-43 Sherd J2 2 Sand plus grog Clay Lumps

9 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.9 Table 6.3. A. Continued. Petrofacies Obs a Petrologists' Temper Type Total Grains Counted Paste Voids Fiber Voids Grog Sample No. Sample Type RNA-44 Sherd K 1 Sand plus fiber temper RNA-45 Sherd K 1 Sand RNA-46 Sherd K 1 Sandy clay (may have crushing features) RNA-47 Sherd K 1 Sand RNA-48 Sherd K 1 Sandy clay (may have crushing features) RNA-49 Sherd O 1 Sandy clay (may have crushing features) RNA-50 Sherd G 1 Sandy clay (may have crushing features) RNA-51 Sherd K 1 Sand + grog + 1-7% crushed rock RNA-52 Sherd J1 1 Sandy clay plus grog RNA-53 Sherd J1 1 Sand + grog + 1-7% crushed rock RNA-54 Sherd J1 1 Sandy clay plus grog RNA-55 Sherd J1 1 Sand + grog + 1-7% crushed rock RNA-56 Sherd J1 1 Sand plus grog RNA-57 Sherd K 1 Sand plus grog RNA-58 Sherd O 1 Sand plus fiber temper RNA-59 Sherd O 1 Sand plus fiber temper RNA-60 Sherd O 2 Sand plus fiber temper RNA-61 Sherd O 1 Sand plus fiber temper RNA-62 Sherd O 1 Sand plus fiber temper RNA-63 Sherd O 1 Sand plus fiber temper RNA-64 Sherd O 1 Sand plus fiber temper RNA-65 Sherd O 1 Sand plus fiber temper RNA-66 Sherd O 1 Sand plus fiber temper RNA-67 Sherd O 1 Sand plus fiber temper RNA-68 Sherd O 1 Sand plus fiber temper RNA-69 Sherd O 1 Sand plus fiber temper RNA-70 Sherd O 1 Sand plus fiber temper RNA-3575 Ethnographic clay O 1 Sand plus fiber temper RNA-3642 Ethnographic clay O 1 Not tempered RNA-6100 Ethnographic clay O 1 Sand plus fiber temper athe "obs" number is used to distinguish among different point counts of the same thin section. Only one point count per thin section is used for statistical purposes. Clay Lumps

10 6.10 Chapter 6 Table 6.3. Point-count data for the thin-sectioned sherds. B. Monocrystalline grains and unknown grains Monocrystalline Grains Sample No. Qtz Kspar Micr Sanid P Plag Plagal Plaggn Musc Biot Chlor Pyr Px Amph Opaq Oliv Epid Sphene Gar Unkn RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA

11 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.11 Table 6.3. B. Continued. Monocrystalline Grains Sample No. Qtz Kspar Micr Sanid P Plag Plagal Plaggn Musc Biot Chlor Pyr Px Amph Opaq Oliv Epid Sphene Gar Unkn RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA

12 6.12 Chapter 6 Table 6.3. Point-count data for the thin-sectioned sherds. C. Metamorphic lithic fragments and monocrystalline grains from gneiss or schist Metamorphic Lithic Fragments Monocrystalline Grains from Gneiss or Schist Sample No. Lma Lmvf Lmss Lmamph Lmt Lmtp Lmm Lmf Sqtz Splag Skspar Smusc Sbiot Schlor Sopaq RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA

13 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.13 Table 6.3. C. Continued. Metamorphic Lithic Fragments Monocrystalline Grains from Gneiss or Schist Sample No. Lma Lmvf Lmss Lmamph Lmt Lmtp Lmm Lmf Sqtz Splag Skspar Smusc Sbiot Schlor Sopaq RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA

14 6.14 Chapter 6 Table 6.3. Point-count data for the thin-sectioned sherds. D. Volcanic and sedimentary lithic fragments Volcanic Lithic Fragments Sedimentary Lithic Fragments Sample No. Lvf Lvfb Lvi Lvm Lvv Lvh Lss Lsa Lsch Lsca Lsca1 Lsca2 Lsca3 Caco RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA

15 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.15 Table 6.3. D. Continued. Volcanic Lithic Fragments Sedimentary Lithic Fragments Sample No. Lvf Lvfb Lvi Lvm Lvv Lvh Lss Lsa Lsch Lsca Lsca1 Lsca2 Lsca3 Caco RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA RNA

16 6.16 Chapter 6 Table 6.4. Qualitative data for the thin-sectioned sherds from the Rio Nuevo Archaeology project. A. Fine fraction characteristics Sample No. Matrix Opacity a Silt Fraction 1 Silt Fraction 2 Silt Fraction 3 Clay Fraction 1 Clay Fraction 2 Lumps in Matrix? RNA Quartz Biotite Plagioclase Quartz and/or RNA Quartz Plagioclase Opaque oxides Quartz and/or Biotite Several Biotite Few RNA Quartz Feldspar Micas Quartz Opaque oxides Several RNA Quartz Biotite Opaque oxides Quartz and/or RNA Quartz Plagioclase Biotite Quartz and/or RNA Quartz Plagioclase Potassium Quartz and/or RNA Quartz Plagioclase Opaque oxides Quartz and/or RNA Quartz Plagioclase Opaque oxides Quartz and/or RNA Quartz Plagioclase Opaque oxides Quartz and/or Biotite None Micas Few Feldspar None Biotite None Biotite Few Biotite Few RNA Quartz Plagioclase Opaque oxides Quartz Feldspar Few RNA Quartz Plagioclase Potassium Quartz and/or RNA Quartz Plagioclase Chlorite Quartz and/or RNA Quartz Plagioclase Opaque oxides Quartz and/or RNA Quartz Plagioclase Opaque oxides Quartz and/or RNA Quartz Micas Quartz and/or Quartz and/or RNA Quartz Plagioclase Opaque oxides Quartz and/or RNA Quartz Plagioclase Biotite Quartz and/or Biotite None Micas Few Micas Several Micas Several Micas Zoned and mottled Micas Few Micas Few

17 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.17 Table 6.4. A. Continued. Sample No. Matrix Opacity a Silt Fraction 1 Silt Fraction 2 Silt Fraction 3 Clay Fraction 1 Clay Fraction 2 Lumps in Matrix? RNA Quartz Plagioclase Opaque oxides Quartz and/or RNA Quartz Biotite Plagioclase Quartz and/or RNA Quartz Biotite Plagioclase Quartz and/or Micas None Micas Zoned, mottled, lumpy, and otherwise highly heterogeneous Micas Few RNA Quartz Microcline Opaque oxides Quartz Feldspar Few RNA Quartz Feldspar Opaque oxides Quartz and/or Opaque oxides Several RNA Quartz Feldspar Opaque oxides Feldspar Micas Few RNA-39 3 Quartz and/or Biotite Opaque oxides Quartz and/or Micas Few RNA-40 3 Quartz Plagioclase Potassium Quartz Quartz and/or RNA-41 3 Quartz Plagioclase Potassium Quartz Quartz and/or RNA-42 3 Quartz Plagioclase Opaque oxides Quartz Feldspar Few None Few RNA-43 2 Quartz Plagioclase Opaque oxides Quartz and/or RNA-44 2 Quartz Biotite Opaque oxides Quartz and/or RNA-45 3 Quartz Plagioclase Opaque oxides Quartz and/or RNA-46 3 Plagioclase Micas None Micas Few Opaque oxides Few Quartz Opaque oxides Quartz Quartz and/or RNA-47 3 Quartz Plagioclase Potassium Quartz and/or RNA-48 3 Quartz Plagioclase Opaque oxides Quartz and/or Few Micas Few Opaque oxides Few RNA-49 2 Quartz Plagioclase Opaque oxides Micas Quartz and/or None Biotite None RNA-50 3 Plagioclase Quartz Biotite Quartz and/or RNA-51 2 Quartz Plagioclase Opaque oxides Quartz and/or Micas None

18 6.18 Chapter 6 Table 6.4. A. Continued. Sample No. Matrix Opacity a Silt Fraction 1 Silt Fraction 2 Silt Fraction 3 Clay Fraction 1 Clay Fraction 2 Lumps in Matrix? RNA-52 2 Quartz Plagioclase Opaque oxides Quartz and/or RNA-53 1 Quartz Plagioclase Opaque oxides Quartz and/or RNA-54 2 Quartz Plagioclase Potassium Quartz and/or RNA-55 2 Plagioclase Quartz Chlorite Quartz Plagioclase RNA-56 2 Quartz Plagioclase Opaque oxides Quartz and/or Micas None Micas Few Micas None Few Micas None RNA-57 2 Quartz Plagioclase Opaque oxides Quartz and/or Micas None RNA-58 1 Plagioclase Quartz Potassium Quartz Feldspar Few Opaque oxides None RNA-59 1 Plagioclase Quartz Opaque oxides Quartz and/or RNA-60 2 Quartz Plagioclase Micas Quartz and/or Opaque oxides None RNA-61 1 Plagioclase Quartz Pyroxene or amphibole Quartz and/or Opaque oxides None RNA-62 1 Plagioclase Quartz Potassium Quartz and/or Opaque oxides None RNA-63 1 Plagioclase Quartz Potassium Quartz Feldspar Few RNA-64 1 Quartz Plagioclase Feldspar Quartz and/or Opaque oxides Several RNA-65 1 Quartz Plagioclase Opaque oxides Quartz Feldspar None RNA-66 1 Quartz Plagioclase Potassium Feldspar Micas Few RNA-67 1 Quartz Plagioclase Micas Feldspar Micas Few RNA-68 1 Quartz Plagioclase Potassium Quartz and/or Micas Few RNA-69 2 Quartz Plagioclase Potassium Feldspar Opaque oxides Few RNA-70 1 Quartz Plagioclase Potassium Feldspar Micas Few amatrix opacity is expressed as an integer from 0 = opaque to 9 = transparent.

19 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.19 Table 6.4. Qualitative data for the thin-sectioned sherds from the Rio Nuevo Archaeology project. B. Sand fraction characteristics Sample No. Finest (mm) Coarsest (mm) Mode (mm) Sorting RNA2-01 Silt (<0.0625) Very coarse sand ( ) Dominant Coarse Grain Accessory Mineral 1 Accessory Mineral 2 Accessory Mineral 3 Bimodal Bimodal Quartz Opaque oxides Plagioclase Biotite RNA2-02 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Opaque oxides Biotite and chlorite Plagioclase RNA2-03 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Opaque oxides Plagioclase Biotite and chlorite RNA2-04 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Tuff of Beehive Peak Tuff of Beehive Peak Quartz Plagioclase RNA2-05 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Microcline Opaque oxides Plagioclase RNA2-06 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase RNA2-07 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase RNA2-08 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase RNA2-09 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase RNA2-10 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase Feldspar Tuff of Beehive Peak Opaque oxides Potassium Biotite Microcline Opaque oxides Potassium Opaque oxides Altered/Chloritized mafics RNA2-11 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Plagioclase Quartz Biotite and chlorite RNA2-12 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase RNA2-13 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Tuff of Beehive Peak RNA2-14 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase Biotite and chlorite Potassium Hypabyssal volcanic, "dirty snowballs" Plagioclase Tuff of Beehive Peak Opaque oxides RNA2-15 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Grog Opaque oxides Plagioclase RNA2-16 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Tuff of Beehive Peak RNA2-18 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Tuff of Beehive Peak Opaque oxides Sherd temper of various sorts Plagioclase Biotite and chlorite

20 6.20 Chapter 6 Table 6.4. B. Continued. Sample No. Finest (mm) Coarsest (mm) Mode (mm) Sorting Dominant Coarse Grain Accessory Mineral 1 RNA2-19 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Tuff of Beehive Peak RNA2-20 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase Accessory Mineral 2 Accessory Mineral 3 Plagioclase Opaque oxides Opaque oxides Micas RNA2-21 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Fiber, nonspecific Biotite Plagioclase RNA2-22 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Microcline Fiber, non-specific Plagioclase RNA2-23 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Fiber, nonspecific RNA2-24 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase RNA-39 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase RNA-40 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase Plagioclase Opaque oxides Opaque oxides Microcline Potassium Opaque oxides RNA-41 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Plagioclase Quartz RNA-42 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Hypabyssal volcanic, "dirty snowballs" RNA-43 Silt (<0.0625) Very coarse sand ( ) Coarse sand ( ) Moderately well Hypabyssal volcanic, "dirty snowballs" RNA-44 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase RNA-45 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase Quartz Plagioclase Opaque oxides Quartz Plagioclase Opaque oxides Potassium Opaque oxides RNA-46 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Plagioclase Quartz Opaque oxides Amphibole RNA-47 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase Potassium Biotite and chlorite RNA-48 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Plagioclase Quartz Opaque oxides Potassium RNA-49 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Plagioclase Schist Potassium RNA-50 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Plagioclase Quartz Biotite Potassium RNA-51 Silt (<0.0625) Very coarse sand ( ) Coarse sand ( ) Moderately poor Quartz Plagioclase Microcline Opaque oxides

21 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.21 Table 6.4. B. Continued. Sample No. Finest (mm) Coarsest (mm) Mode (mm) Sorting RNA-52 Silt (<0.0625) Very coarse sand ( ) Coarse sand ( ) RNA-53 Silt (<0.0625) Granule (>2.0) Very coarse sand ( ) RNA-54 Silt (<0.0625) Granule (>2.0) Very coarse sand ( ) RNA-55 Silt (<0.0625) Very coarse sand ( ) RNA-56 Silt (<0.0625) Very coarse sand ( ) Moderately sorted Moderately sorted Moderately poor Dominant Coarse Grain Accessory Mineral 1 Quartz Plagioclase Undifferentiated felsic volcanic Quartz Plagioclase Bimodal Bimodal Plagioclase Potassium Very coarse sand ( ) RNA-57 Silt (<0.0625) Granule (>2.0) Very coarse sand ( ) RNA-58 Silt (<0.0625) Granule (>2.0) Very coarse sand ( ) RNA-59 Silt (<0.0625) Granule (>2.0) Coarse sand ( ) RNA-60 Silt (<0.0625) Granule (>2.0) Coarse sand ( ) RNA-61 Silt (<0.0625) Granule (>2.0) Coarse sand ( ) RNA-62 Silt (<0.0625) Granule (>2.0) Coarse sand ( ) RNA-63 Silt (<0.0625) Granule (>2.0) Very coarse sand ( ) RNA-64 Silt (<0.0625) Granule (>2.0) Very coarse sand ( ) RNA-65 Silt (<0.0625) Very coarse sand ( ) Medium sand ( ) Moderately sorted Quartz Plagioclase Accessory Mineral 2 Undifferentiated felsic volcanic Accessory Mineral 3 Opaque oxides Quartz Grog Opaque oxides Undifferentiated felsic volcanic Undifferentiated felsic volcanic Undifferentiated felsic volcanic Opaque oxides Biotite and chlorite Opaque oxides Moderately Plagioclase Quartz Microcline Biotite and chlorite well Moderately Microcline Quartz Plagioclase Caliche; granular sorted carbonate grains Moderately Plagioclase Microcline Quartz Granite sorted Moderately Potassium Plagioclase Quartz Undifferentiated poor felsic volcanic Moderately Plagioclase Microcline Quartz Granite poor Poorly sorted Plagioclase Microcline Quartz Unknown Moderately poor Moderately poor Moderately poor Microcline Plagioclase Microcline Plagioclase Microcline Plagioclase RNA-66 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Plagioclase Fiber, nonspecific RNA-67 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Fiber, nonspecific RNA-68 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Quartz Fiber, nonspecific RNA-69 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Plagioclase Fiber, nonspecific RNA-70 Silt (<0.0625) Granule (>2.0) Bimodal Bimodal Plagioclase Fiber, nonspecific Quartz Granite Quartz Clay lumps Quartz Granite Quartz Microcline Micas Plagioclase Microcline Plagioclase Quartz Microcline Quartz Microcline

22 6.22 Chapter 6 Temper Type Analysis The diverse assortment of temper types in this set of sherds requires additional explanation (see Table 6.4). In addition to sand temper, sherds with sand plus grog and sand plus fiber temper were encountered. In all but one of the 56 thin sections, the ceramicist s assessment of temper type concurs with that seen under the petrographic microscope (Table 6.5). The single exception is RNA-44, a very finegrained sherd with a dark paste. In this sherd, fiber temper is clearly visible in the thin section, but the fibers are small and the paste is very dark, making it impossible to see the fiber voids under the low-powered binocular stereomicroscope. Additionally, the petrographers characterized some tempers as sandy clay or sandy clay plus fiber instead of the ceramicist s characterization of sand and sand plus fiber. These more detailed characterizations under the petrographic microscope reflect the presence of crushing features on the sand grains features that are only visible in thin section. Thus, the ceramicist s sand is equivalent to the petrographers sandy clay. A more complete discussion of the anthropological and statistical implications of the use of sand versus sandy clay is found later in this chapter. Statistical Implications of Temper Type Variations With sand-tempered sherds, the sand temper data are simply submitted for analysis. With more complex mixtures for example, sand plus grog the non-sand phase must be excluded from consideration during the statistical analysis process. For the Rio Nuevo sherds, the following statistical adaptations were used. The sand-tempered sherds in the Tucson Basin are straightforward; therefore, all sand-sized grains are counted. A record of the number of matrix and voids encountered while counting is kept, making a full volumetric composition of the paste available. Figure 6.2 is a photomicrograph of a Beehive Petrofacies sand-tempered sherd, illustrating common grain sizes and shapes for sand-tempered sherds. The sand plus grog-tempered sherds in the Tucson Basin commonly have sand temper in the grog (Figure 6.3). Thus, anything that may be encountered within the grog grain was counted as grog, although a separate list of grog composition was collected. The grog is not included in the compositional analysis of the sand temper for provenance analysis. The fiber-tempered sherds in the Tucson Basin commonly have large, elongated voids, frequently with charred remains of plant material (Figures ). The plant structure is sometimes retained, and the voids may also have dark, carbonized margins. When counting, the characteristic fiber voids are tallied separately from the bubble voids commonly seen in ceramics. Voids are not included in the statistical provenance analyses of sand. Ethnographic evidence indicates the source of the fiber in these ceramics is manure, presumably horse manure (Fontana et al. 1962). In addition to the fiber, all the fiber-tempered pottery also contains sand. This sand could be added intentionally, although it is more likely a component of the clay selected for pottery production. Ethnographic research conducted in the mid-twentieth century indicates pedologically derived clays forming on alluvial parent material were a common source for local historic Native American potters (Fontana et al. 1962:Figure 41). These materials are rich in sandsized grains. The clays were ground up (Fontana et al. 1963:Figure 42), then horse manure was added to make the clay paste. We have noted crushing features on the sand grains in the fiber-tempered pottery, which supports the ethnographic reports. Compositionally, the sands naturally included in these clays are directly related to their provenance. However, their composition may differ slightly from our reference sands, which have experienced less chemical weathering than sediments subjected to soil formation. Behaviorally, the sand is not temper; that is, it was not added to the clay to change the properties of the material (Shepard 1995). Finally, Whittlesey (1997) has suggested that some amount of sand may be introduced into the clay body from the horse manure. Although we have collected horse manure to test this hypothesis, we are still debating a suitable method for extracting and quantifying sand fraction that may be included in the manure. Visually, sparse grains of sand can be seen in the manure, but the quantity introduced into the clay body would be volumetrically very low. For comparison, three ethnographic samples of raw and prepared clay were obtained from the Arizona State Museum (ASM). One of the samples is from the San Xavier area; the remaining samples are from farther west on the Tohono O odham Reservation. All three samples were collected and prepared by O odham potters (Fontana et al. 1962: ). Test briquettes were made from the samples; these were subsequently thin sectioned and point counted (Figures ). The raw clay sample contains 33 percent sand, while the prepared clay samples, which have added manure, have percent sand. All three samples are at the high end of sand content compared with the fiber-tempered archaeological pottery, which ranges from percent sand, with a mean of 27 percent (Figure 6.9). Visual examination of horse manure and the point-count data from ethnographic samples suggest a small amount of

23 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.23 Table 6.5. Comparison of temper type assessments made by the ceramicist (low magnification) and the petrographers (high magnification) for sherds from the Rio Nuevo Archaeology project. Sample Number Ceramic Type Ceramicist's Temper Type Petrographer's Temper Type Results RNA2-01 Indeterminate red Sand Sandy clay Agree RNA2-02 Indeterminate red Sand Sand Agree RNA2-03 Indeterminate red Sand Sand Agree RNA2-04 Unspecified plain ware Sand Sand Agree RNA2-05 Indeterminate red Sand Sand Agree RNA2-06 Indeterminate red Sand Sand Agree RNA2-07 Unspecified plain ware Sand Sand Agree RNA2-08 Indeterminate red Sand Sand Agree RNA2-09 Indeterminate red Sand Sand Agree RNA2-10 Indeterminate red Sand Sand Agree RNA2-11 Indeterminate red Sand Sand Agree RNA2-12 Indeterminate red Sand Sandy clay Agree RNA2-13 Indeterminate red Sand plus grog Sand plus grog Agree RNA2-14 Indeterminate red Sand plus grog Sand plus grog Agree RNA2-15 Indeterminate red Sand plus grog Sandy clay plus grog Agree RNA2-16 Indeterminate red Sand plus grog Sand plus grog Agree RNA2-17 Sobaipuri Plain (folded rim) Sand plus grog Sand plus grog Agree RNA2-18 Unspecified plain ware Sand plus grog Sand plus grog Agree RNA2-19 Unspecified plain ware Sand plus grog Sand Agree RNA2-20 Unspecified plain ware Sand plus grog Sandy clay plus grog Agree RNA2-21 Papago Plain Sand plus manure/fiber Sand plus manure/fiber Agree RNA2-22 Papago Red Sand plus manure/fiber Sand plus manure/fiber Agree RNA2-23 Papago Red Sand plus manure/fiber Sand plus manure/fiber Agree RNA2-24 Indeterminate red Sand Sand Agree RNA-39 Sobaipuri Plain (folded rim) Sand Sand Agree RNA-40 Unspecified plain ware Sand Sand Agree RNA-41 Sobaipuri Plain (folded rim) Sand Sand Agree RNA-42 Unspecified plain ware Sand Sand Agree RNA-43 Unspecified plain ware Sand plus grog Sand plus grog Agree RNA-44 Papago Red Sand Sand plus manure/fiber Disagree RNA-45 Papago Plain Sand Sand Agree RNA-46 Unspecified plain ware Sand Sandy clay Agree RNA-47 Indeterminate red Sand Sand Agree RNA-48 Unspecified plain ware Sand Sandy clay Agree RNA-49 Sobaipuri Plain (folded rim) Sand Sandy clay Agree RNA-50 Unspecified plain ware Sand Sandy clay Agree RNA-51 Sobaipuri Plain (folded rim) Sand plus grog Sand plus grog Agree RNA-52 Sobaipuri Plain (folded rim) Sand plus grog Sandy clay plus grog Agree RNA-53 Unspecified plain ware Sand plus grog Sand plus grog Agree RNA-54 Indeterminate red Sand plus grog Sandy clay plus grog Agree RNA-55 Sobaipuri Plain (folded rim) Sand plus grog Sand plus grog Agree RNA-56 Unspecified plain ware Sand plus grog Sand plus grog Agree RNA-57 Indeterminate red Sand plus grog Sand plus grog Agree

24 6.24 Chapter 6 Table 6.5. Continued. Sample Number Ceramic Type Ceramicist's Temper Type Petrographer's Temper Type Results RNA-58 Papago Plain Sand plus manure/fiber Sand plus manure/fiber Agree RNA-59 Papago Red Sand plus manure/fiber Sand plus manure/fiber Agree RNA-60 Papago Red Sand plus manure/fiber Sand plus manure/fiber Agree RNA-61 Papago Plain Sand plus manure/fiber Sand plus manure/fiber Agree RNA-62 Papago Plain Sand plus manure/fiber Sand plus manure/fiber Agree RNA-63 Papago Red Sand plus manure/fiber Sand plus manure/fiber Agree RNA-64 Papago Plain Sand plus manure/fiber Sand plus manure/fiber Agree RNA-65 Papago Red Sand plus manure/fiber Sand plus manure/fiber Agree RNA-66 Papago Plain Sand plus manure/fiber Sand plus manure/fiber Agree RNA-67 Papago Plain Sand plus manure/fiber Sand plus manure/fiber Agree RNA-68 Papago Red Sand plus manure/fiber Sand plus manure/fiber Agree RNA-69 Papago Plain Sand plus manure/fiber Sand plus manure/fiber Agree RNA-70 Papago Plain Sand plus manure/fiber Sand plus manure/fiber Agree sand could have been introduced into the paste from manure temper, although the bulk of the sand-sized grains in the temper were probably a natural component of the clay. Behavioral Implications of the Material Types After full consideration of the data, we included all sand-sized grains from fiber-tempered pottery in our statistical analysis, on the assumption that the sand is predominantly derived from the clay itself, and that it reflects the provenance of that material. We recognize that our sand samples may not be the perfect source material from which to match sandy clays derived from soils, but we assert that they are similar enough to compare statistically. Therefore, the sand in fiber-tempered pottery is treated as if it were sand temper for statistical purposes. However, the collection of sandy clays from soils is a different behavior than the collection of sand to temper clay. Ethnographic examples collected from around the world show that potters sometimes collect clay resources from farther away than sand resources (Arnold 1985; Heidke 2006; Heidke et al. 2002; Heidke et al. 2006; Miksa and Heidke 1995). Most clays are collected within 4 km of the pottery production locations (Figure 6.10). An examination of a box-and-whiskers plot of 150 distance-to-clay resource measurements shows the median distance to clay as 2 km, with the upper hinge (75 percent) at 4 km. There are 16 outliers between 8 km and 50 km. Of these 16 outliers, only one is specified as foot transport of the material. The remaining distance-to-resource data do not list the specific mode of transport, Figure 6.2. Photomicrograph of a Beehive Petrofacies sandtempered sherd. Figure 6.3. Photomicrograph of sherd RNA-52, tempered with Beehive Petrofacies sand plus grog. (Photograph was taken at 13.2x magnification under crossed nicols; note the sand temper in the dark grog fragment.)

25 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.25 Figure 6.4. Photomicrograph of sherd RNA2-22, showing prismatic fiber voids, carbon rim, and some remnant fiber structure. (Photograph was taken at 13.2x magnification under plane polarized light.) Figure 6.7. Photomicrograph of an unfired briquet made from an ethnographic collection of prepared clay (ASM number E6100) collected by Fontana et al. (1962). (Note the abundant fiber in the paste; photograph was taken at 13.2x magnification under plane polarized light.) Figure 6.5. Photomicrograph of sherd RNA-44, showing elongated fiber voids, one of which is bent around a sand grain. (Photograph was taken at 13.2x magnification under plane polarized light.) Figure 6.8. Photomicrograph of an unfired briquet made from an ethnographic collection of prepared clay (ASM number E6100) collected by Fontana et al. (1962). (Closeup of structural detail; photograph was taken at 33x magnification under cross polarized light.) so some non-foot transport distances may be included (Heidke et al. 2006). Examination of the ethnographic and historic literature for O odham and Sobaipuri potters of southern and western Arizona suggest their distance-to-clay resource measurements would have been within the 4 km estimate, at least while human labor was the primary mode of transportation. We use this distance in calculating clay procurement by historic Native American potters. Temper Composition Analysis Figure 6.6. Photomicrograph of sherd RNA2-23, showing detail of a fiber void with remnant plant structure. (Photograph was taken at 33x magnification under crossed nicols.) Temper composition of the Rio Nuevo sherds was characterized by Heidke. Because only 56 of 2,373 characterized sherds were selected for thin-section

26 6.26 Chapter 6 analysis, the overall thin-section proportion for this data set is 2.4 percent (Table 6.6). This is approximately half the usual proportion of thin sections selected for verification purposes (Miksa and Heidke 2001). The low proportion is due to a number of circumstances. First, sherds assigned to the unspecified generic and specific temper composition group were not sampled due to their low information value. The high number of fine-grained or fiber-tempered historic sherds in this data set led to a high number of unspecified temper designations, because temper could not be distinguished at low, reflected light magnification. This group includes 666 of the Percent Sand Sample Type Fiber-tempered sherd Ethnographic clay Figure 6.9. Dot density graph showing the proportion of sand in the sand plus fiber-tempered sherds versus the fiber-tempered ethnographically collected prepared clays. Other Rock Gneiss Ash/Tuff Sand Clay Distance (km) Figure Ethnographic distance-to-resource measurements, by resource type. 2,373 sherds, or 28 percent of the data set. This group was sampled at a deliberately low rate for this project, due to its low information value and the likelihood that the sherds belonged to multiple compositions. Sherds belonging to the Fine Paste generic group were not thin sectioned due to their lack of sand-sized grains. Sherds assigned to the Santan or Gila Butte Schist Plus Sand and Metamorphic Core Complex generic groups, and the Catalina and Tortolita petrofacies, were not sampled because they represent a very low proportion of the complete data set. The Twin Hills Petrofacies was sampled at a lower rate because Heidke has shown his ability to recognize these petrofacies on previous projects (Heidke 2000, 2003a, 2003b, 2006; Heidke et al. 1998). Although Heidke has demonstrated a similar success rate with the Beehive Petrofacies sand-tempered sherds, this group is still being sampled at a higher rate to explore the limits of this composition, especially at its southern edge where it meets the Black Mountain Petrofacies. Sherds assigned to the volcanic generic group with an unspecified petrofacies were sampled at a low rate, due to their lower information value and the likelihood that they would represent several petrofacies. In the remaining composition groups, sampling rates of approximately 4-10 percent were used to test the temper characterizations. This sampling rate is adequate to test the diversity of the sample and the accuracy of the ceramicist s temper characterizations within the sampled groups. After the petrographic analysis was complete, sherds were submitted as unknowns for classification by the current Tucson Basin discriminant analysis model (Miksa 2006), following standard statistical analysis methods for point-counted sherds (Heidke and Miksa 2000; Miksa and Heidke 2001). The discriminant model used for this project considers only the 18 petrofacies in the Tucson Basin proper. It includes 243 sands, of which 214 are classified correctly by the model, for an accuracy of 88 percent. The model comprises nine nested discriminant analysis models. The output at each modeling level is used as the input for the next level, as detailed in Heidke and Miksa (2000). The point-count parameters and calculated parameters used in each level of the model are shown in Table 6.7, and a schematic view of how the nested models relate to each another is provided in Figure 6.11.

27 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.27 Table 6.6. Proportion of thin sections by concatenated generic temper source and specific temper source groups, Rio Nuevo Archaeology project. Number of Sherds (number of thin sections) in the Detailed Ceramic Analysis Set, by Site b Generic Temper Source a Specific Temper Source a BB:13:13 BB:13:481 BB:13:6 Total Sherds Total Thin Sections Thin Section Proportion Unspecified Unspecified 82 (2) 13 (0) 571 (4) Fine paste Unspecified 0 (0) 4 (0) 91 (0) Santan or Gila Butte Unspecified 0 (0) 0 (0) 5 (0) schist plus sand Metamorphic core Catalina 0 (0) 0 (0) 11 (0) complex Metamorphic core Unspecified 0 (0) 0 (0) 15 (0) complex Granitic Unspecified 171 (15) 0 (0) 117 (2) Granitic Tortolita 0 (0) 0 (0) 3 (0) Mixed volcanic and Unspecified 39 (4) 0 (0) 3 (0) granitic Granitic and mixed Santa Cruz River 0 (0) 0 (0) 239 (9) lithic Granitic and mixed Unspecified 25 (2) 0 (0) 1 (0) lithic Volcanic Unspecified 17 (2) 0 (0) 390 (4) Volcanic Beehive 50 (5) 0 (0) 218 (5) Volcanic Twin Hills 12 (0) 0 (0) 296 (2) Column totals 396 (30) 17 (0) 1,960 (26) 2, afrom ceramicist's temper characterization. ball sites are AZ # (ASM). Results Discriminant analysis results for the compositional analysis are shown in Table 6.8. Fifty-three of the 56 thin-sectioned sherds were given final petrofacies assignments. It is informative to examine the sherds in terms of the generic and specific temper groups assigned during the detailed analysis. Discriminant analysis assigns all submitted samples to the closest group in multidimensional space, even though the samples may be far from the closest group. Thus, discriminant assignments are checked for accuracy before a final petrofacies assignment is made. The six sherds with both generic and specific temper source unspecified were difficult to classify even with quantitative petrographic data. One was thought to belong to the Rincon Petrofacies by the petrographer. The discriminant analysis also classified the sherd as Rincon Petrofacies, so the final assignment is accepted as Rincon Petrofacies. Two of the sherds have a final classification as indeterminate. The petrographer s temper assignment did not match that of the discriminant analysis, and after much additional inspection and comparison of composition proportions, none of the assignments could be affirmed as correct. Consequently, these sherds have Indeterminate temper classifications. One of the sherds was thought to be extrabasinal by the petrographers. It was assigned to the Airport Petrofacies in the discriminant analysis, but does not have any volcanic grain types in common with that petrofacies. The temper in this sherd bears some similarity to rocks located west of Avra Valley and should be compared with source materials from the Altar Valley should they become available. Finally, two of the unspecified sherds were thought to belong to the Black Mountain Petrofacies by the petrographer. Both were assigned to Black Mountain Petrofacies by the discriminant analysis. Their final assignment is Black Mountain Petrofacies. Seventeen of the thin-sectioned sherds were assigned to the Granitic Sand, Unspecified Petrofacies group. These sherds come from historic Native American pots with fiber temper. The petrographers characterized them as coming from either the Black

28 6.28 Chapter 6 Table 6.7. Point count parameters and calculated parameters used for each discriminant analysis model. Family Level Granitic- Metamorphic Generic Level Granitic, Rich in Microcline Granitic, Rich in Heavy Minerals Volcanic, Generic Level Volcanic, Rich in Feldspars Volcanics Only, Generic Level Tucson Mountains, East Tucson Mountains, North and West Petrofacies A, G, K, O, P B, E1, E2, E3, S Bv, I J1, J2, J3 L, M, Mw TQtz X X X X X X X X X Kspar X X Micr X X X X TKspar X K X X X TPlag X X X X X X X TMusc X X TBiotchlor X X X Mica X X PlagPyr X TOpaq X X X PyrOpaq X Epid X X X Pyrepid X Hmin X X Lma2 X Lmmf X X Lmatp X Lmmftp X Lm_Musc X Lm X X X Lvf2 X X X Lvm2 X X Lvmf2 X Lvv X Lvh X X Lv X X X Ls X X X Lsclas X X Lscaco X

29 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.29 "Family" level model all petrofacies Granitic-Metamorphic petrofacies Volcanic rock-bearing petrofacies Granitic sands rich in heavy minerals: B, E1, E2, E3, S Granitic sands rich in microcline: A, G, K, O, P Volcanic sands rich in : Bv, I Volcanic sands (abundant volcanic lithic fragments, no other grain types of note) Eastern Tucson Mountains: J1, J2, J3 Northern and western Tucson Mountains: L, M, Mw Figure Schematic diagram illustrating the relationships among the nested discriminant models in the Tucson Basin Petrofacies model. Mountain or Sierrita petrofacies. The discriminant analysis also assigned 16 of the sherds to one of these two petrofacies, although the petrographer s assignment does not necessarily match the discriminant analysis assignment in any given case. These sherds have been assigned to the final group Black Mountain or Sierrita petrofacies. There is considerable compositional gradation in this group between the two petrofacies, and it is difficult to assign them to one petrofacies or another. This may be a case in which the application of sand point-count data to the provenance characterization of sandy pedogenic clay is less exact than preferred. It may also reflect use of the resources in a gradational boundary zone between the two petrofacies (see the case study discussion below). To further complicate the situation, the Black Mountain Petrofacies was not adequately sampled and described at the time of the sherd characterization, so Heidke was unable to identify the sherds to specific petrofacies. Since that time, Heidke has learned to recognize the specific grain combination that characterizes the Black Mountain Petrofacies and to distinguish it from the Sierrita Petrofacies (Heidke and Miksa 2006). The sherd that was not assigned to either the Black Mountain or Sierrita petrofacies by the discriminant analysis model merits a specific note. Sample RNA- 45 was assigned to the Twin Hills Petrofacies by the discriminant analysis model. This sample has a higher than usual proportion of a microgranite that is generally found in the Black Mountain Petrofacies. The microgranite is counted on the LVH parameter (see Table 6.2), but is not the same as the spherulitic hypabyssal volcanic found in the Twin Hills Petrofacies, which is also counted on the LVH parameter. Although this type of overlap rarely causes problems, in this case, it led to a faulty discriminant analysis characterization. Four sherds characterized by the ceramicist as belonging to the Mixed Volcanic and Granitic generic group with an unspecified petrofacies were characterized as belonging to the Black Mountain Petrofacies by the petrographers. Three of the four were classified as Black Mountain Petrofacies by the discriminant analysis; the fourth was assigned to the Airport Petrofacies. The volcanic grains in the four samples are consistent with the mixture of volcanic lithic fragments seen on the western side of the Santa Cruz River near the Black Mountain Petrofacies, not with those seen on the eastern side of the Santa Cruz River in the Airport Petrofacies. The final assignment for the four sherds is the Black Mountain Petrofacies.

30 6.30 Chapter 6 Table 6.8. Discriminant analysis results and petrofacies characterizations for the point-counted sherds. Sample Number Ceramic Type RNA2-01 Indeterminate red RNA2-02 Indeterminate red RNA2-03 Indeterminate red RNA2-04 Unspecified plain ware RNA2-05 Indeterminate red RNA2-06 Indeterminate red RNA2-07 Unspecified plain ware RNA2-08 Indeterminate red RNA2-09 Indeterminate red RNA2-10 Indeterminate red RNA2-11 Indeterminate red RNA2-12 Indeterminate red RNA2-13 Indeterminate red RNA2-14 Indeterminate red RNA2-15 Indeterminate red RNA2-16 Indeterminate red RNA2-17 Sobaipuri Plain (folded rim) RNA2-18 Unspecified plain ware RNA2-19 Unspecified plain ware RNA2-20 Unspecified plain ware Ceramicist's Generic Temper Source Ceramicist's Petrofacies Petrographer's Petrofacies Discriminant Analysis Predicted Petrofacies Final Petrofacies Assignment Unspecified Unspecified Rincon Rincon Rincon Unspecified Unspecified Beehive Catalina Volcanic Indeterminate Unspecified Unspecified Extrabasinal Airport Extrabasinal Volcanic Beehive Beehive Golden Gate Beehive Granitic and mixed lithic Santa Cruz River Black Hills Santa Rita Airport Granitic and Santa Cruz Beehive Airport Airport mixed lithic River Granitic and Santa Cruz Beehive Airport Airport mixed lithic River Granitic and Santa Cruz Beehive Santa Rita Airport mixed lithic River Granitic and Santa Cruz Beehive Airport Airport mixed lithic River Granitic and Santa Cruz Black Hills Airport Airport mixed lithic River Granitic and Santa Cruz Beehive Airport Airport mixed lithic River Granitic and Santa Cruz Beehive Airport Airport mixed lithic River Volcanic Unspecified Beehive Golden Gate Beehive Volcanic Unspecified Beehive Beehive Beehive Volcanic Unspecified Beehive Beehive Beehive Volcanic Unspecified Beehive Beehive Beehive Volcanic Beehive Beehive Beehive Beehive Volcanic Beehive Beehive Beehive Beehive Volcanic Beehive Beehive Golden Gate Beehive Volcanic Beehive Beehive Beehive Beehive RNA2-21 Papago Plain Unspecified Unspecified Granitic Airport Indeterminate RNA2-22 Papago Red Granitic Unspecified Black Hills Sierrita Black Hills or Sierrita RNA2-23 Papago Red Granitic Unspecified Black Hills Twin Hills Black Hills or Sierrita RNA2-24 Indeterminate red Granitic and mixed lithic Santa Cruz River Beehive Beehive Airport RNA-39 Sobaipuri Plain Unspecified Unspecified Black Hills Black Hills Black Hills (folded rim) RNA-40 Unspecified Volcanic Beehive Beehive Beehive Beehive plain ware RNA-41 Sobaipuri Plain Volcanic Beehive Black Hills Black Hills Beehive (folded rim) RNA-42 Unspecified plain ware Volcanic Twin Hills Twin Hills Twin Hills Twin Hills

31 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.31 Table 6.8. Continued. Sample Number RNA-43 Ceramicist's Generic Temper Source Ceramicist's Petrofacies Petrographer's Petrofacies Discriminant Analysis Predicted Petrofacies Final Petrofacies Assignment Ceramic Type Unspecified Volcanic Twin Hills Twin Hills Twin Hills Twin Hills plain ware RNA-44 Papago Red Granitic Unspecified Black Hills Black Hills Black Hills or Sierrita RNA-45 Papago Plain Granitic Unspecified Black Hills Black Hills Black Hills or Sierrita RNA-46 Unspecified Mixed volcanic Unspecified Black Hills Airport Black Hills plain ware and granitic RNA-47 Indeterminate Mixed volcanic Unspecified Black Hills Black Hills Black Hills red and granitic RNA-48 Unspecified Mixed volcanic Unspecified Black Hills Black Hills Black Hills plain ware and granitic RNA-49 Sobaipuri Plain Granitic and Unspecified Sierrita Airport Airport (folded rim) mixed lithic RNA-50 Unspecified Granitic and Unspecified Santa Rita Santa Rita Airport plain ware mixed lithic RNA-51 Sobaipuri Plain Unspecified Unspecified Black Hills Black Hills Black Hills (folded rim) RNA-52 Sobaipuri Plain Volcanic Unspecified Beehive Beehive Beehive (folded rim) RNA-53 Unspecified Volcanic Unspecified Beehive Beehive Beehive plain ware RNA-54 Indeterminate Volcanic Beehive Beehive Beehive Beehive red RNA-55 Sobaipuri Plain Volcanic Beehive Beehive Beehive Beehive (folded rim) RNA-56 Unspecified Volcanic Beehive Beehive Beehive Beehive plain ware RNA-57 Indeterminate Mixed volcanic Unspecified Black Hills Black Hills Black Hills red and granitic RNA-58 Papago Plain Granitic Unspecified Sierrita Sierrita Black Hills or Sierrita RNA-59 Papago Red Granitic Unspecified Sierrita Black Hills Black Hills or Sierrita RNA-60 Papago Red Granitic Unspecified Sierrita Black Hills Black Hills or Sierrita RNA-61 Papago Plain Granitic Unspecified Sierrita Sierrita Black Hills or Sierrita RNA-62 Papago Plain Granitic Unspecified Sierrita Black Hills Black Hills or Sierrita RNA-63 Papago Red Granitic Unspecified Sierrita Black Hills Black Hills or Sierrita RNA-64 Papago Plain Granitic Unspecified Sierrita Sierrita Black Hills or Sierrita RNA-65 Papago Red Granitic Unspecified Sierrita Sierrita Black Hills or Sierrita RNA-66 Papago Plain Granitic Unspecified Sierrita Sierrita Black Hills or Sierrita RNA-67 Papago Plain Granitic Unspecified Sierrita Sierrita Black Hills or Sierrita RNA-68 Papago Red Granitic Unspecified Sierrita Sierrita Black Hills or Sierrita RNA-69 Papago Plain Granitic Unspecified Sierrita Sierrita Black Hills or Sierrita RNA-70 Papago Plain Granitic Unspecified Sierrita Sierrita Black Hills or Sierrita

32 6.32 Chapter 6 Two sherds were characterized by the ceramicist as belonging to the Granitic Plus Mixed Lithic generic group with an unspecified petrofacies. One was characterized as the Sierrita Petrofacies by the petrographers, while the other was characterized as belonging to the Santa Rita Petrofacies. In the discriminant analysis model, the first was characterized as belonging to the Airport Petrofacies, while the second was characterized as belonging to the Santa Rita Petrofacies. On petrographic review, both samples were assigned to the Airport Petrofacies; however, this is a provisional assignment. Additional information is necessary to assess the compositional range of both petrofacies, especially the distal ends near the Santa Cruz River. Nine samples were characterized by the ceramicist as belonging to the Granitic Plus Mixed Lithic generic group and the Santa Cruz River Petrofacies. These samples 1 The Airport Petrofacies composition had not been defined at the time Heidke characterized the temper provenance of these sherds F Figure QmFLt ternary plot showing sherds assigned to the Airport Petrofacies, along with sand from the Airport, Beehive, Black Mountain, Santa Rita, and Sierrita petrofacies. were characterized by the petrographers as belonging to the Beehive and Black Mountain petrofacies. The discriminant analysis classification for six of the samples is the Airport Petrofacies. Two samples are classified as members of the Santa Rita Petrofacies. One sample was classified as a member of the Beehive Petrofacies, although it lacks the distinctive volcanic grains of that petrofacies. Extensive petrographic review shows that the initial characterization by both the ceramicist and the petrographers was incorrect. 1 A QmFLt ternary plot of the composition shows that the temper composition of the sherds overlaps with the composition of Airport Petrofacies sands, but not with those of the Santa Rita Petrofacies (Figure 6.12). Volcanic lithic fragments in the sherds are consistent with those of Airport Petrofacies sands. Therefore, the final assignment of these sherds is to the Airport Petrofacies. With recent improvements in the description of the Airport Petrofacies, and improved characterizations to help distinguish between Airport and Santa Cruz River petrofacies sands in hand-sample, it should be possible to make this distinction more easily in the future. Six samples were assigned by the ceramicist to the volcanic generic group, with petrofacies unspecified. These samples were characterized by the petrographers as Beehive Petrofacies. The discriminant analysis classification for five of the samples is the Beehive Petrofacies, while the sixth is to the Golden Gate Petrofacies. Petrographic review of the samples suggests all six belong to the Beehive Petrofacies. Ten samples were assigned by the ceramicist to the volcanic generic group and the Beehive Petrofacies. Nine of the 10 sherds were characterized as Beehive Petrofacies by the petrographers and the discriminant analysis model; the tenth was characterized as Black Mountain Petrofacies by the petrographers and the discriminant analysis model. After petrographic review, all 10 samples were assigned to the Beehive Petrofacies. Two samples were assigned by the ceramicist to the volcanic generic group and the Twin Hills Petrofacies. Both samples were also assigned to the Twin Hills Petrofacies by the petrographers and the discriminant analysis model. The final assignment of Twin Hills Petrofacies is accepted for these samples. Discussion Qm The data presented above show that sands or sandy clays from four petrofacies were used to manufacture the Native American ceramics recovered from the sites investigated during the Rio Nuevo Archaeology project. These four petrofacies include the following Santa Rita Airport Beehive Black Mountain Sierrita Sherd Lt

33 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.33 The Beehive Petrofacies, which is south-southwest of the Rio Nuevo sites. It is known as a pottery production area since at least A.D The Beehive Petrofacies is approximately 4 km from the project area sites, so it is not considered a local production source for the sites. The Airport Petrofacies, which covers much of the Tucson Basin floor. The Clearwater site is situated just across the Santa Cruz River from the northwestern tip of the Airport Petrofacies; therefore, it is a local source of sand for the site. The Tucson Presidio is located within the Airport Petrofacies. The Black Mountain Petrofacies is located approximately 11 km south of the project area sites; it is not a local production source. The Sierrita Petrofacies, located approximately 13 km south of the project area sites is not a local production source. Combining the final characterization data given above and in Table 6.8 with the proportion of the ceramics represented by the thin-sectioned sherds, 49 percent of the sherds are in a petrographically verified group assigned to a petrofacies. Forty-five percent of the study set remains in petrographically verified groups not assigned to a petrofacies. Approximately 5 percent of the sherds in the detailed study set were not included in the petrographic verification study. Examination of Table 6.9 shows that source areas are not distributed equally between the sites. For instance, the San Agustín Mission locus has a much larger proportion of sherds identified as originating in the Beehive or Twin Hills petrofacies than the Tucson Presidio, while the Tucson Presidio has a slight majority of the sherds originating in the Black Mountain or Sierrita petrofacies, although the difference is not as pronounced as that for the volcanic petrofacies. The time differences between these two sites may play a role in this difference: The San Agustín Mission locus dates to the Spanish period, A.D to 1821, with most of the excavated features dating between 1771 and The Tucson Presidio dates slightly later, to both the Spanish and Mexican periods, circa A.D to Without additional data and time periods, it is difficult to assess the nature of this pattern. Fortunately, several other sites in the downtown Tucson area have been excavated in recent years and petrographically verified data sets spanning the historic time periods from the Spanish to American Statehood periods are available. A small case study using selected, well-dated features from the Rio Nuevo project sites and other nearby sites has been used to evaluate the relationship among pottery production location, pottery technology, and time in the historic Tucson Basin. CASE STUDY: THE EFFECTS OF HISTORIC EVENTS ON O ODHAM POTTERY PRODUCTION IN HISTORIC TUCSON, ARIZONA In the Historic era, Native Americans in the Tucson area produced ceramic vessels for their own use, as well as for sale or trade to the growing Euro-American community. As noted above, historic ceramics were commonly tempered with sand, sand plus grog, or manure. The pottery production locations and technology of manufacture changed through time. This study explores these changes. Native American pottery from eight sites and site components in the Tucson area, excavated by Desert Archaeology, Inc., over the last 10 years (Figures ; Table 6.10) was examined. The sites were occupied throughout the Historic era, from approximately A.D to 1929; that is, from the time of Spanish occupation, through the Mexican period, and into the American Territorial and American Statehood periods. The sites are located along the eastern and southern flanks of the Tucson Mountains. To explore changes in production technology and provenance over time, a collection of 1,097 decorated sherds and plain ware rim sherds from well-dated contexts spanning 12 distinct time intervals at the eight sites was selected for detailed ceramic analysis (Figure 6.15; Table 6.11). The contexts are dated by historic artifact content, and it is these dates that have been applied to the ceramics. As noted above, information such as ceramic form, style, vessel size, and detailed notes on decorative elements was recorded for each sherd. Additionally, temper attributes were identified by the project ceramicist, so that the sherds could be compared with known sand temper sources available in Tucson. A random sample stratified by ware and temper characterization was used to select 67 of the sherds for thin sectioning so that detailed petrographic analyses could be completed. Overall, a 6.1 percent sample was thin sectioned, although this sample is not distributed evenly through all sampled time intervals (see Figure 6.15). The sherds were point counted and submitted for discriminant analysis, as detailed above. Results Results of the discriminant analysis were very strong. Most of the pottery can be assigned to petrofacies found near the central and southern Tucson Mountains. Much of it was produced in the Beehive Petrofacies, a known production area since prehistoric times. Limited numbers of sherds with Twin Hills Petrofacies sands were recovered. This is also a

34 6.34 Chapter 6 Table 6.9. Number of sherds and proportion of thin sections in each final provenance group. Number of Sherds (proportion of sherds) in the Detailed Ceramic Analysis Set, by Site b Generic Temper Source a Specific Temper Source a Final Temper Characterization Total Sherds Not Characterized to Petrofacies Total Sherds Characterized to Petrofacies BB:13:13 BB:13:481 BB:13:6 Unspecified Unspecified Unspecified (0.03) 13 (0.01) 571 (0.024) Granitic Unspecified Black Mountain or Sierrita petrofacies Mixed volcanic and granitic Granitic and mixed lithic Granitic and mixed lithic Unspecified Black Mountain Petrofacies (0.07) 0 (0.00) 117 (0.005) (0.02) 0 (0.00) 3 (0.001) Santa Cruz River Airport Petrofacies (0.00) 0 (0.00) 239 (0.001) Unspecified Airport Petrofacies (0.01) 0 (0.00) 1 (0.000) Volcanic Unspecified Unspecified (0.01) 0 (0.00) 390 (0.016) Volcanic Beehive Beehive Petrofacies (0.02) 0 (0.00) 218 (0.009) Volcanic Twin Hills Twin Hills Petrofacies (0.01) 0 (0.00) 296 (0.012) Column totals 1,073 1, (0.17) 13 (0.01) 1,835 (0.077) Notes: Total sherds in the study set: 2,373 Total sherds in a petrographically verified group: 2,244 Percentage of total study set in a petrographically verified petrofacies: Percentage of total study set not in a petrographically verified petrofacies: Percentage of total study set not petrographically verified: 5.4 afrom ceramicist's temper characterization. ball site numbers are AZ # (ASM)

35 Petrographic Analysis of Pottery for the Rio Nuevo Project 6.35 Figure Overview of archaeological sites in the case study, showing nearby petrofacies. León Farmstead Figure Close-up of archaeological sites in the case study, showing site names and locations in downtown Tucson. known prehistoric production area. Interestingly, a large number of pots produced in the Airport Petrofacies were recovered. Finally, a majority of the pottery recovered from these sites was manufactured in the Black Mountain Petrofacies, or in either the Black Mountain or Sierrita petrofacies. This latter group is a set of ceramics that grades in composition from one petrofacies to the other. The two petrofacies are adjacent and closely related, and their boundary is a diffuse geomorphic transition zone on the bajada of the Sierrita Mountains, with alluvial tributaries moving freely back and forth across the landscape. Much of the pottery was likely produced along the boundary zone between the two petrofacies, near San Xavier del Bac Mission. Two historic villages are noted in a late nineteenth century map of the San Xavier area; they straddle this boundary zone (Chillson 1888). The potters may have lived in or near these villages. The temper type analysis confirms long-held notions about the change from sand or sand plus grog temper to fiber temper over time (Figure 6.16). Almost all the ceramics recovered from the San Agustín Mission locus, from features dating between 1771 and 1821, are tempered with sand or sand plus grog, as are the ceramics recovered from features at the Tucson Presidio dating from 1810 to In the ceramics recovered from units dating to the 1820s and 1830s at the Tucson Presidio, fiber temper begins to appear, but other temper types are also used. In the next time interval, , fiber temper jumps to more than 50 percent of the total pottery recovered from the León farmstead, AZ BB:13:505 (ASM). By the 1870s, fiber-tempered pottery comprises the majority of that recovered from all of the sites. By 1890, it is the only temper being used in Native American pottery. The trends in temper composition reflect those seen in temper type (Figure 6.17). In the earliest San Agustín Mission deposits, the pottery was being produced primarily in the Beehive and Airport petrofacies. The Airport Petrofacies source is local to those sites and to Tucson at the time. The Beehive Petrofacies source is 4 km to the south. There is a very small amount of pottery from the Twin Hills Petrofacies, which is local to the sites. Starting in the early 1820s, the Black Mountain and Sierrita petrofacies